Universidad de Santiago de Chile, Departamento de Física, Avda. Víctor Jara 3493, 9170124 Santiago, Chile.
Center for the Development of Nanoscience and Nanotechnology, CEDENNA, Avda. Libertador Bernardo O'Higgins 3363, 9170124 Santiago, Chile.
Nanotechnology. 2023 Feb 9;34(16). doi: 10.1088/1361-6528/acb557.
Three dimensional magnetic textures are a cornerstone in magnetism research. In this work, we analyze the stabilization and dynamic response of a magnetic hopfion hosted in a toroidal nanoring with intrinsic Dzyaloshinskii-Moriya interaction simulating FeGe. Our results evidence that unlike their planar counterparts, where perpendicular magnetic anisotropies are necessary to stabilize hopfions, the shape anisotropy originated on the torus symmetry naturally yields the nucleation of these topological textures. We also analyze the magnetization dynamical response by applying a magnetic field pulse to differentiate among several magnetic patterns. Finally, to understand the nature of spin wave modes, we analyze the spatial distributions of the resonant mode amplitudes and phases and describe the differences among bulk and surface modes. Importantly, hopfions lying in toroidal nanorings present a non-circularly symmetric poloidal resonant mode, which is not observed in other systems hosting hopfions.
三维磁性纹理是磁性研究的基石。在这项工作中，我们分析了内禀 Dzyaloshinskii-Moriya 相互作用模拟 FeGe 的环形纳米环中磁 Hopfion 的稳定和动态响应。我们的结果表明，与平面磁 Hopfion 不同，平面磁 Hopfion 需要垂直磁各向异性来稳定磁 Hopfion，而环上的形状各向异性自然产生了这些拓扑纹理的成核。我们还通过施加磁场脉冲来分析磁化动力学响应，以区分几种磁模式。最后，为了理解自旋波模式的性质，我们分析了共振模式幅度和相位的空间分布，并描述了体模和表面模之间的差异。重要的是，位于环形纳米环中的 Hopfion 呈现出非圆对称的极向共振模式，这在其他承载 Hopfion 的系统中是观察不到的。
